HD tune Thread

[CyberDruid]

I see some ups and downs on a lot of dreives I bench that are repeatable and consistent from bench mark to benchmark and I associated it with processes in the OS...but since you are using two different OS I guess Iwas wrong.

Anyone know what that the dip is caused by? You got me curious now.

Side note...

It should be obvious why you get a faster more responsive desktop when you partion the OS...the fast part of the drive is on the outside of the platter as shown on the graphs...as the arm swings in speed drops significantly.

Not all dirves have such a dramatic tailing off of speed. But in general the first third is pretty fast and rest starts gettting slower, so divide capacity by 3 and set partition size to that number for optimal results.

 

[TIGR]

An illustration of CyberDruid's explanation that drives get slower toward the "end" of the drive (the inside of the platters where they spin most slowly) is my 4x Raptox X RAID 0 benches:

4x Raptor X RAID 0 600GB array: 270MB/sec average transfer, 8.8ms access
4x Raptor X RAID 0 20GB array: 329MB/sec average transfer, 5.8ms access

This is why I believe RAID 0 does have a place in regular desktop usage. By combining drives and then creating small RAID 0 arrays at the beginning of the drives using Matrix RAID, one can not only significantly outpace 10k drives' throughput but also approach if not equal their access times. My 4x Ultrastar 1TB (7200rpm) 558GB RAID 0 array:

4x Ultrastar RAID 0 558GB array: 329.3MB/sec average transfer, 8.8ms access

And that is with a 558GB array. I believe a 150GB RAID 0 array with those drives would beat a Raptor-X drive's access time of 8.5ms.

If I don't shut up, I'll never sell my Raptors. =P

Hope it helps.

 

[NeotonicDragon3]

Here are my 2 Hard drives lol

1) 160GB Western Digital Cavalier SATA II 7,200 RPM

lol
2) Seagate FreeAgent Desktop SATA300 7,200RPM

wooo

 

[powerspec]

My hard drive at work.

powerspec Western Digital Caviar Blue WD800JD 80GB 8MB Cache SATA 45.9MB/s

This here is my laptop hard drive, man is it slow
Travelstar 40GB 4200RPM 2MB Cache IDE

 

[CStylen]

CStylen
2 X 300GB Velociraptors RAID 0
AVG: 192.4 MB/sec

2 X 300GB Velociraptors at 322GB RAID 0
AVG: 209.4 MB/sec

2 X 300GB Velociraptors at 162GB RAID 0
AVG: 217.4 MB/sec

1 300gb Velociraptor
AVG: 103.2 MB/sec

What impresses me most about these drives is how much more quiet they are over the old raptors...

 

[TIGR]

Thanks CStylen, good to see those benches.

 

[powerspec]

CStylen my i ask, im thinking of getting another Velociraptor and doing raid 0 with them, do you see any difference in speed in windows/apps by going with 2 Velociraptor over just 1?

 

[CStylen]

I haven't installed my OS or anyhting else on them yet, I was just testing to see if they would be significantly faster than my two 150GB Raptor RAID 0...

Judging by the numbers, it would be safe to say that you would see an improvement.

 

[Woody112]

2x Velociraptors---average 183.9
was expecting a little more from these drives. Owell should have better scores after I rma my bad drive. Keep getting "A drive in a raid 0 volume is failing". Just seeing if I can smoke it before I send it back.

 

[Woody112]

2x Velociraptors---average 183.9
was expecting a little more from these drives. Owell should have better scores after I rma my bad drive. Keep getting "A drive in a raid 0 volume is failing". Just seeing if I can smoke it before I send it back.

It is now dead owell. Just pulled it out and sending it back tomorrow. Benched it all night with sandra and HDTune. Enterprise class drive.. Ha.Ha.Ha. Please what a marketing ploy. Hopefully the next one will live up to to the task and not is't name. If you know what I mean.

Anyways I just posted the new build in the case gallery take a look and cast a vote. Be glad to hear what everyone has to say.

http://www.techpowerup.com/gallery/1737.html

 

[suraswami]

Suraswami, 2 x WD SATAII 160GB, 113.9 MB/sec
1 x WD 80GB IDE, 47.5 MB/sec.

 

[CarolinaKSU]

One question I have been pondering to myself is why do most of the graphs on HD Tune drop off as the test progresses? And what causes the spikes to be smaller and the graph flatter on other benches?

 

[theeldest]

One question I have been pondering to myself is why do most of the graphs on HD Tune drop off as the test progresses? And what causes the spikes to be smaller and the graph flatter on other benches?

Imagine that there are "tracks" on the platters in your hard drive. Each track is a ring around the platter. The rings on the outside of the platter can hold more data because they're longer.

But the platter spins at the same speed no matter where the data is being read from. So imagine it takes a 1/100th of a second to read a track (no matter how much data is on the track), and there is 1MB on the outer ring, and .1MB on the inner most ring.

The hard drive could read 100 MB / second on the outside track and 10MB / second on the inside track.


It's called Zoned Constant Angular Velocity.



So as the drive reads from the beginning (outside of the platter) to the end, it slows down because there is less data on each ring.

 

[theeldest]

Just another comment.

One thing I didn't understand was why the graphs aren't linear? Why do they curve down?

As you get toward the center, the rate that date can be read decreases at a rate proportional to the radius of the track. Since each track is the same width, as you get closer to the center, the rate that the read speed changes should remain constant (ie, the graphs should be straight lines).


Then I figured it out. (and I'm posting it here incase anyone else has had the same question).

The rate *does* change in a linear way. The read speed is linear to the *track*, but not to the place on the disk.

Imagine a platter with 5 tracks. The tracks (from the outside going in) have 5MB, 4MB, 3MB, 2MB, and 1MB of data. Everytime the read head switches tracks, it gets a bit slower since it's closer to the center.

So it reads the first 5MB at it's highest speed, then slows down a bit to read the next 4MB. After those 4MB, it slows down some more to read the next 3MB. After those 3MB it slows down a bit to read the next 2MB. After it reads those 2MB, it slows down a bit to read the next 1MB.

Since the HDTune graphs are speed vs *position in MB* and not *track*. Everytime it switches a track, it reads less data before slowing down again. So the speed decrease seen from switching from the first 5MB to the second 4MB is the same as between the second to last 2MB and the last 1MB.


So it should look something like this:

|
| -----
|      ----
|          ---
|             --
|               -
|____________________

Eureka!


*to all of you that already knew this, please don't ruin my moment. *

 

[Woody112]

Woody112 2 x 300GB WD Velociraptors at 160GB raid 0 --average 208.4MB/s

 

[mlee49]

Fujitsu 60 GB notebook drive

 

[Deleted member 3]

I wonder why burst rates are so irregular. Mine are crap, those Intel controllers are extremely high. I'm assuming they use system memory for cache?

 

[btarunr]

I wonder why burst rates are so irregular. Mine are crap, those Intel controllers are extremely high. I'm assuming they use system memory for cache?

That's seems to be a known issue with RAID users. When burst speeds are lower than average speeds, you know the reading is flawed.

 

[Wile E]

I wonder why burst rates are so irregular. Mine are crap, those Intel controllers are extremely high. I'm assuming they use system memory for cache?

Yeah. It's called write back cache.

 

[Deleted member 3]

Yeah. It's called write back cache.

I know, it's what screws up my performance when I turn it on. My controller uses PC133. As soon as I use the cache for anything speed drops to <133MB/s. Interesting that the Intel controllers use system memory though.

Still doesn't explain why my burst is so crap though.

 

[alexp999]

Just an idea for DarkEgo. any chance you could split the list up a bit. Getting a bit big!

Maybe Raid and non raid for a start...

 

[TonyMontana]

My Hardrive test

So here are my results not spectaclair but i'm happy not the slowest

 

[Deleted member 3]

So here are my results not spectaclair but i'm happy not the slowest

CPU usage is quite high. Though seeing your specs that's no surprise. Still very annoying when copying huge files and trying to do other things. I guess you'll be posting new results after Christmas.

 

[Flamingsupernova]

Flamingsupernova
Western Digital Caviar 320gb 3gb/s
Average 61.3 Mb/s

 

[stordoff]

2x WD6400AAKS - Intel RAID 0 (AAM Disabled)

Write-back Cache Off:

Not sure what caused the dip around 20% - Burst seems a little low, HD Tach measures over 300MB/Sec

Write-back Cache On:

Going to get a third

Should I seperate the first 30% for data, the rest for programs or leave as full drive?